Grog
On 21 Aug 1740 the term 'Grog' came in to Royal Navy vocabulary thanks to Vice Admiral Edward Vernon. Vernon was known by his nickname 'Old Grog' which refered to his favourite jacket which was made from Grogram; he was seldom seen without it. Vernon was a great one for trying to improve procedures, a spin-off from this was to improve health and sobriety in the 'lower deck' ranks in order to improve overall efficiency and performance (Senior ratings continued to be allowed to have their 'tot' neat, as an incentive for boarding party crews and medicinally).
This he achieved by watering down the daily rum ration 'the tot' (which was an 1/8 pint of Rum) with water and citrus juice. The citrus juice, in the form of Lemons or Limes being added to sweeten foul water and, as was found out at a later date, prevented scurvy. (side note here to all our colonial brothers - this is why we Brits got the nickname 'Limeys'). The other reason for watering down the Rum, is that when water is added to most spirits, it doesn't keep for more than a day or so, and thus could not be stockpiled.
Grog remained a daily perk until July 31st 1970, an infamous day forever known in the Royal Navy as 'Black Tot Day'.